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FFmpeg/libavformat/4xm.c
Mans Rullgard 3383a53e7d lavu: replace int/float punning functions 
The existing functions defined in intfloat_readwrite.[ch] are
both slow and incorrect (infinities are not handled).

This introduces a new header with fast, inline conversion
functions using direct union punning assuming an IEEE-754
system, an assumption already made throughout the code.

The one use of Intel/Motorola extended 80-bit format is
replaced by simpler code sufficient under the present
constraints (positive normal values).

The old functions are marked deprecated and retained for
compatibility.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-12-11 18:47:19 +00:00

360 lines
12 KiB
C
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/*
* 4X Technologies .4xm File Demuxer (no muxer)
* Copyright (c) 2003 The ffmpeg Project
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* 4X Technologies file demuxer
* by Mike Melanson (melanson@pcisys.net)
* for more information on the .4xm file format, visit:
* http://www.pcisys.net/~melanson/codecs/
*/
#include "libavutil/intreadwrite.h"
#include "libavutil/intfloat.h"
#include "avformat.h"
#include "internal.h"
#define RIFF_TAG MKTAG('R', 'I', 'F', 'F')
#define FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
#define LIST_TAG MKTAG('L', 'I', 'S', 'T')
#define HEAD_TAG MKTAG('H', 'E', 'A', 'D')
#define TRK__TAG MKTAG('T', 'R', 'K', '_')
#define MOVI_TAG MKTAG('M', 'O', 'V', 'I')
#define VTRK_TAG MKTAG('V', 'T', 'R', 'K')
#define STRK_TAG MKTAG('S', 'T', 'R', 'K')
#define std__TAG MKTAG('s', 't', 'd', '_')
#define name_TAG MKTAG('n', 'a', 'm', 'e')
#define vtrk_TAG MKTAG('v', 't', 'r', 'k')
#define strk_TAG MKTAG('s', 't', 'r', 'k')
#define ifrm_TAG MKTAG('i', 'f', 'r', 'm')
#define pfrm_TAG MKTAG('p', 'f', 'r', 'm')
#define cfrm_TAG MKTAG('c', 'f', 'r', 'm')
#define ifr2_TAG MKTAG('i', 'f', 'r', '2')
#define pfr2_TAG MKTAG('p', 'f', 'r', '2')
#define cfr2_TAG MKTAG('c', 'f', 'r', '2')
#define snd__TAG MKTAG('s', 'n', 'd', '_')
#define vtrk_SIZE 0x44
#define strk_SIZE 0x28
#define GET_LIST_HEADER() \
fourcc_tag = avio_rl32(pb); \
size = avio_rl32(pb); \
if (fourcc_tag != LIST_TAG) \
return AVERROR_INVALIDDATA; \
fourcc_tag = avio_rl32(pb);
typedef struct AudioTrack {
int sample_rate;
int bits;
int channels;
int stream_index;
int adpcm;
int64_t audio_pts;
} AudioTrack;
typedef struct FourxmDemuxContext {
int width;
int height;
int video_stream_index;
int track_count;
AudioTrack *tracks;
int64_t video_pts;
float fps;
} FourxmDemuxContext;
static int fourxm_probe(AVProbeData *p)
{
if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
(AV_RL32(&p->buf[8]) != FOURXMV_TAG))
return 0;
return AVPROBE_SCORE_MAX;
}
static int fourxm_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
AVIOContext *pb = s->pb;
unsigned int fourcc_tag;
unsigned int size;
int header_size;
FourxmDemuxContext *fourxm = s->priv_data;
unsigned char *header;
int i, ret;
AVStream *st;
fourxm->track_count = 0;
fourxm->tracks = NULL;
fourxm->fps = 1.0;
/* skip the first 3 32-bit numbers */
avio_skip(pb, 12);
/* check for LIST-HEAD */
GET_LIST_HEADER();
header_size = size - 4;
if (fourcc_tag != HEAD_TAG || header_size < 0)
return AVERROR_INVALIDDATA;
/* allocate space for the header and load the whole thing */
header = av_malloc(header_size);
if (!header)
return AVERROR(ENOMEM);
if (avio_read(pb, header, header_size) != header_size){
av_free(header);
return AVERROR(EIO);
}
/* take the lazy approach and search for any and all vtrk and strk chunks */
for (i = 0; i < header_size - 8; i++) {
fourcc_tag = AV_RL32(&header[i]);
size = AV_RL32(&header[i + 4]);
if (fourcc_tag == std__TAG) {
fourxm->fps = av_int2float(AV_RL32(&header[i + 12]));
} else if (fourcc_tag == vtrk_TAG) {
/* check that there is enough data */
if (size != vtrk_SIZE) {
ret= AVERROR_INVALIDDATA;
goto fail;
}
fourxm->width = AV_RL32(&header[i + 36]);
fourxm->height = AV_RL32(&header[i + 40]);
/* allocate a new AVStream */
st = avformat_new_stream(s, NULL);
if (!st){
ret= AVERROR(ENOMEM);
goto fail;
}
avpriv_set_pts_info(st, 60, 1, fourxm->fps);
fourxm->video_stream_index = st->index;
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_4XM;
st->codec->extradata_size = 4;
st->codec->extradata = av_malloc(4);
AV_WL32(st->codec->extradata, AV_RL32(&header[i + 16]));
st->codec->width = fourxm->width;
st->codec->height = fourxm->height;
i += 8 + size;
} else if (fourcc_tag == strk_TAG) {
int current_track;
/* check that there is enough data */
if (size != strk_SIZE) {
ret= AVERROR_INVALIDDATA;
goto fail;
}
current_track = AV_RL32(&header[i + 8]);
if((unsigned)current_track >= UINT_MAX / sizeof(AudioTrack) - 1){
av_log(s, AV_LOG_ERROR, "current_track too large\n");
ret= -1;
goto fail;
}
if (current_track + 1 > fourxm->track_count) {
fourxm->tracks = av_realloc(fourxm->tracks,
(current_track + 1) * sizeof(AudioTrack));
if (!fourxm->tracks) {
ret = AVERROR(ENOMEM);
goto fail;
}
memset(&fourxm->tracks[fourxm->track_count], 0,
sizeof(AudioTrack) * (current_track + 1 - fourxm->track_count));
fourxm->track_count = current_track + 1;
}
fourxm->tracks[current_track].adpcm = AV_RL32(&header[i + 12]);
fourxm->tracks[current_track].channels = AV_RL32(&header[i + 36]);
fourxm->tracks[current_track].sample_rate = AV_RL32(&header[i + 40]);
fourxm->tracks[current_track].bits = AV_RL32(&header[i + 44]);
fourxm->tracks[current_track].audio_pts = 0;
if( fourxm->tracks[current_track].channels <= 0
|| fourxm->tracks[current_track].sample_rate <= 0
|| fourxm->tracks[current_track].bits < 0){
av_log(s, AV_LOG_ERROR, "audio header invalid\n");
ret= -1;
goto fail;
}
i += 8 + size;
/* allocate a new AVStream */
st = avformat_new_stream(s, NULL);
if (!st){
ret= AVERROR(ENOMEM);
goto fail;
}
st->id = current_track;
avpriv_set_pts_info(st, 60, 1, fourxm->tracks[current_track].sample_rate);
fourxm->tracks[current_track].stream_index = st->index;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_tag = 0;
st->codec->channels = fourxm->tracks[current_track].channels;
st->codec->sample_rate = fourxm->tracks[current_track].sample_rate;
st->codec->bits_per_coded_sample = fourxm->tracks[current_track].bits;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
st->codec->bits_per_coded_sample;
st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
if (fourxm->tracks[current_track].adpcm){
st->codec->codec_id = CODEC_ID_ADPCM_4XM;
}else if (st->codec->bits_per_coded_sample == 8){
st->codec->codec_id = CODEC_ID_PCM_U8;
}else
st->codec->codec_id = CODEC_ID_PCM_S16LE;
}
}
/* skip over the LIST-MOVI chunk (which is where the stream should be */
GET_LIST_HEADER();
if (fourcc_tag != MOVI_TAG){
ret= AVERROR_INVALIDDATA;
goto fail;
}
av_free(header);
/* initialize context members */
fourxm->video_pts = -1; /* first frame will push to 0 */
return 0;
fail:
av_freep(&fourxm->tracks);
av_free(header);
return ret;
}
static int fourxm_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
FourxmDemuxContext *fourxm = s->priv_data;
AVIOContext *pb = s->pb;
unsigned int fourcc_tag;
unsigned int size;
int ret = 0;
unsigned int track_number;
int packet_read = 0;
unsigned char header[8];
int audio_frame_count;
while (!packet_read) {
if ((ret = avio_read(s->pb, header, 8)) < 0)
return ret;
fourcc_tag = AV_RL32(&header[0]);
size = AV_RL32(&header[4]);
if (pb->eof_reached)
return AVERROR(EIO);
switch (fourcc_tag) {
case LIST_TAG:
/* this is a good time to bump the video pts */
fourxm->video_pts ++;
/* skip the LIST-* tag and move on to the next fourcc */
avio_rl32(pb);
break;
case ifrm_TAG:
case pfrm_TAG:
case cfrm_TAG:
case ifr2_TAG:
case pfr2_TAG:
case cfr2_TAG:
/* allocate 8 more bytes than 'size' to account for fourcc
* and size */
if (size + 8 < size || av_new_packet(pkt, size + 8))
return AVERROR(EIO);
pkt->stream_index = fourxm->video_stream_index;
pkt->pts = fourxm->video_pts;
pkt->pos = avio_tell(s->pb);
memcpy(pkt->data, header, 8);
ret = avio_read(s->pb, &pkt->data[8], size);
if (ret < 0){
av_free_packet(pkt);
}else
packet_read = 1;
break;
case snd__TAG:
track_number = avio_rl32(pb);
avio_skip(pb, 4);
size-=8;
if (track_number < fourxm->track_count && fourxm->tracks[track_number].channels>0) {
ret= av_get_packet(s->pb, pkt, size);
if(ret<0)
return AVERROR(EIO);
pkt->stream_index =
fourxm->tracks[track_number].stream_index;
pkt->pts = fourxm->tracks[track_number].audio_pts;
packet_read = 1;
/* pts accounting */
audio_frame_count = size;
if (fourxm->tracks[track_number].adpcm)
audio_frame_count -=
2 * (fourxm->tracks[track_number].channels);
audio_frame_count /=
fourxm->tracks[track_number].channels;
if (fourxm->tracks[track_number].adpcm){
audio_frame_count *= 2;
}else
audio_frame_count /=
(fourxm->tracks[track_number].bits / 8);
fourxm->tracks[track_number].audio_pts += audio_frame_count;
} else {
avio_skip(pb, size);
}
break;
default:
avio_skip(pb, size);
break;
}
}
return ret;
}
static int fourxm_read_close(AVFormatContext *s)
{
FourxmDemuxContext *fourxm = s->priv_data;
av_freep(&fourxm->tracks);
return 0;
}
AVInputFormat ff_fourxm_demuxer = {
.name = "4xm",
.long_name = NULL_IF_CONFIG_SMALL("4X Technologies format"),
.priv_data_size = sizeof(FourxmDemuxContext),
.read_probe = fourxm_probe,
.read_header = fourxm_read_header,
.read_packet = fourxm_read_packet,
.read_close = fourxm_read_close,
};
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